Dictionary

pernicious vomiting of pregnancy See hyperemesis gravidarum.

personality disorder A disorder characterized by the long-standing use of mechanisms of coping in an inappropriate, stereotyped, and maladaptive manner. Personality disorders are enduring and persistent styles of behavior and thought, not atypical episodes. The personality disorders encompass a group of behavioral disorders that are different and distinct from the psychotic and neurotic disorders. The…

perspiration 1 The secretion of fluid by the sweat (sudoriferous) glands. These small, tubular glands are situated within the skin and in the subcutaneous tissue under it. They discharge fluid through tiny openings in the surface of the skin. Perspiration serves at least two purposes: It removes waste products such as urea and ammonia, and…

Perthes disease See Legg-Calvé-Perthes disease.

pertussis A communicable, potentially deadly illness that is characterized by fits of coughing followed by a noisy, “whooping” indrawn breath. Pertussis is caused by the bacterium Bordetella pertussis. The illness is most likely to affect young children, but it sometimes appears in teenagers and adults, even those who have been previously immunized. When teenagers and…

perichondritis Inflammation of the perichondrium.

perichondrium A dense membrane that is composed of fibrous connective tissue that closely wraps all cartilage except the cartilage in joints, which is covered by a synovial membrane.

perichondroma A benign tumor that arises from the perichondrium.

perimenopause See menopause transition.

perinatal Pertaining to the period immediately before and after birth. The perinatal period is defined in diverse ways. Depending on the definition, it starts at the 20th to 28th week of gestation and ends 1 to 4 weeks after birth.

perinatal transmission See vertical transmission.

perinatalogist An obstetrical subspecialist who is concerned with the care of the mother and fetus when there is a higher-than-normal risk of complications. Most perinatologists are obstetricians. A high-risk baby is often cared for by a perinatologist before birth and by a neonatologist after birth.